Air bag switch machine

ABSTRACT

A trailable switch machine has been provided wherein a switch machine mechanism actuates a set of railroad switch points reciprocally to normal and reverse positions. A control means selectively actuates the mechanism to the desired position in accordance with an input signal. The control means comprises means magnetically responsive to the position of the switch rails including a magnet laterally disposed relative to the normal and reverse positions of the switch rails and a switch means disposed so as to cooperate with the proximity of the magnet. The switch means selectively actuates the control means for changing the position of the rails when the relative position of the switch means and the magnet is altered by the trailing of the switch points. Energy storage means maintains the input signal for a period relative to a minimum actuation time of the control apparatus.

Unite ties Patent i 1 moron [72] Inventor RaymondGCoolt [54] AIR BAG SWiTClii MACHINE 7 Claims, 5 Drawing 1F igs.

[52] US. Cl 246/250, 92/39, 246/318 [51] InLCl 18611504 [50] Field of Search 92/39;

FOREIGN PATENTS 828,705 1/1952 Germany Primary Examiner-Arthur L. LaPoint Assistant Exarrziner-Ge0rge H. Libman Attorney-l-larold S. Wynn AliiSTitACT: A trailable switch machine has been provided wherein a switch machine mechanism actuates a set of railroad switch points reciprocally to normal and reverse positionsv A control means selectively actuates the mechanism to the desired position in accordance with an input signal. The control means comprises means magnetically responsive to the position of the switch rails including a magnet laterally disposed relative to the normal and reverse positions of the switch rails and a switch means disposed so as to cooperate with the proximity of the magnet. The switch means selectively actuates the control means for changing the position of the rails when the relative position of the switch means and the magnet is altered by the trailing of the switch points. Energy v storage means maintains the input signal for a period relative to a minimum actuation time ofthe control appara us.

sum 1 OF 3 PATENTEU M824 IS?! AIR BAG SWITCH MACHINE BACKGROUND OF INVENTION This invention relates to switch machines and in particular to fluid actuated devices having electropneumatic controls.

In certain railroad and industrial yard applications, a switch machine requiring minimum electrical power controls and having a simple and relatively maintenance free mechanism is desirable. I-Ieretofore many machines of the pneumatic type have required expensive piston and cylinder drive mechanisms which require periodic adjustment and overhauling due to wear of the cylinder walls. In certain applications, it may not be economically feasible to utilize such a machine because of its high initial cost and its periodic maintenance requirements. Motor driven units may sometimes be incorporated into such a yard operation; however, where electrical power is either limited or difficult to install, pneumatic machines may be more useful. Many industrial complexes have both electrical and mechanical power readily available; however, it is sometimes more economical to provide compressed air or other fluid to the switches than to provide for electrical power systems. The relative size of the machine is also a consideration which must be anticipated. For example, in main line railroad operations, heavy duty machinery of a substantial size is often utilized incorporating many interlocking devices for guaranteeing fail-safe operation in remotely controlled areas. In industrial yards, however, the because of the presence of operating crews in the area, this consideration is reduced and other safety devices may be installed which require a considerably smaller amount of space and an appreciable reduction in cost.

With a simple actuating mechanism and a relatively small machine, the cost of each unit can be reduced to such a point that possible purchasers of such devices would consider power drive machines rather than manually operated devices. While the initial cost of each of these machines may be somewhat higher than a manually actuated switch stand, the relative differences between the costs of this machine and other power actuated machines is such that it would be economically feasible to consider machine of the present invention over a manually operated device.

It is therefore an object of the invention to provide a relatively inexpensive fluid actuated switch machine.

It is another object of the invention to provide a machine having an electropneumatic control utilizing a minimum of electrical power.

It is another object of the invention to provide a compact and relatively simple actuating mechanism.

These and other objects are discussed in the specification with reference to the following drawings.

DESCRIPTION OF THE DRAWINGS FIG. I is a plan view of showing the machine connected to switch points in its proper environment;

FIG. 2 is a top elevation of the machine of the present invention with the cover removed;

FIG. 3 is a view of the yoke assembly;

FIG. i is a side elevation of the machine along line lA-llA', and

FIG. 5 is a schematic drawing of the electropneumatic controls of the invention.

SUMMARY OF INVENTION The present invention provides for a trailable switch machine for reciprocally actuating a set of railroad switch points to normal and reverse positions. A control means selectively actuates the mechanism to the desired position in accordance with an input signal. The control means comprises means magnetically responsive to the position of the switch rails including a magnet laterally disposed relative to the normal and reverse positions of the switch rails and a switch means disposed so as to cooperate with the proximity of the magnet. The switch means selectively actuates the control means for changing the position of the: rails when the relative position of the switch means and the magnet is altered by trailing of the switch points. Energy storage means maintains the input signal for a period relative to a minimum actuation time of the control apparatus.

DESCRIPTION OF PREFERRED EMBODIMENTS FIG. I shows the switch machine It) mounted adjacent to the rails ill for throwing the switch points 12 between normal or straight through operation along rails 11 or reverse for switching to curved rails Ill. Actuator bar 13 couples the switch points 12 to the machine It]. In. the preferred embodiment, the machine receives compressed air via pneumatic control valve M, the operation of which will be explained in greater detail with reference to FIGS. 2, and A. The machine receives commands from a remote location for actuating the air valve M to the desired mode for moving the switch to either the normal or reverse positions. Machine lit) also includes a point detector responsively actuated by the trailing of the switch points which activates the switch machine 10 for power trailing the points I2 whenever said points are trailed by a railroad car shown illustratively as wheels 15 approaching the switch points from the upper left of FIG. I;

In FIG. 2, the switch machine 10, including a housing 16 having a laterally disposed guide way 17-17 in the left wall thereof. An operating mechanism included in the housing comprises air bags lid-13 fixed at opposite ends to the right and left walls of the housing 16 respectively and at their other ends to a slidably mounted yoke mechanism which engages the guide way for reciprocal movement therein. The yoke mechanism 19 illustrated in FIG. 3 includes a collar 20 engaging the air bags 18 and 18' at their movable ends.

The yoke 19 further comprises guide members 23-21 which pass through the guide way I7-ll.7' respectively and are joined at the far left by alignment plate 22. The alignment plate 22 engages the actuator bar l3 which in turn is con nected to the switch points 112. The air bags l8lltl' are respectively filled and emptied when normal and reverse operation of the switch is desired. That is, when the air bag 18 is filled and I3 is emptied, as shown in the drawing, the switch points are in the normal position. Input air pipes 23-23 feed a fluid to the bags in accordance with the mod-e of fluid control 114. In this invention the source of fluid will be assumed to be air because of its convenience and ready availability. Fluid control I4 is a four-way air valve which alternately provides com pressed air to air bags 18 and I8 and provides an exhaust outlet 24-24' for the bags respectively.

Control M may be manually actuated by selective actuation of push buttons 25 and 25'. However, it is intended that this device be remotely controlled and electrical solenoids are ineluded in the fluid control 14 for selectively actuating the valve for filling and emptying the bags in accordance with the desired position of the switch. This electrical solenoid will be described in further detail with reference to FIG. 5.

A point detector 26 is incorporated into the housing for actuating the switch machine to an opposite position whenever the switch points 12 are trailed. This electromechanical sequence is described with respect to FIG. 5. The point detector 26 includes switches 27-27 preferably of the reed type and a magnet 28 mounted to the collar 20 such that when the switch machine is in its extreme positions shown by phantom lines N AND R, indicating normal and reverse positions respectively, the magnet 28 will be in the proximity of the respective switch 27' and 27 and draw the reed contact located therein towards the magnet. Whenever the points 12 are trailed. the magnet 28 is moved away from its adjacent switch removing its influence from the switch allowing it to close and through the electrical circuit of FIG. 5 actuates the fluid control 114 to change the position of the switch to the opposite mode.

The electropneumatic control of the machine is now described with respect to the circuit diagram of FIG. 5. All of the components to the left and right side of battery E are substantially identical and as such they will be numbered respectively as a specific number and that same number primed for the corresponding element and under the conditions hereinafter set forth whatever occurs to cause a normal actuation occurs similarly to actuate the device to the reverse, upon selective actuation of the corresponding element of each part of the circuit.

The circuit is shown with the machine in the normal position at rest. Input terminals 50 and 50' are connected to a suitable switching mechanism which can be manually or automatically controlled from a central location. The polarity on the input terminals 50-50 calls for a normal actuation of the switch machine and pole-changing of these terminals 50-50 requires that the machine be switched to the reverse position. The circuit for actuating the switch machine to the normal position can be traced as follows. From positive energy at terminal 50 to forward bias diode 51 through relay 52 energizing same to common terminal 53. Energization of relay 52 picks up contacts 54 and 55. The closing of front contact 55 provides a circuit for energizing solenoid 56 which controls fourway valve 14. When valve 14 is actuated by the solenoid 56, the machine switches to the normal position. This circuit for energizing solenoid 56 is traced as follows. From positive energy of the battery E through wires 57, 58 and 59 through the relay 56 energizing same, wire 60 to front contact 55 and thence to common terminal 53. Actuation of the relay 56 provides for motion in the interior apparatus of four-way valve for directing the air into bag 18 and out of bag 18. A momentary energization of terminal 50 by positive energy, as for example, by a spring actuated switch may not provide energy for a sufficient time to fully actuate the four-way valve 14 through relay 56. In order to provide for such an occurrence, an electrical tank circuit is included in this schematic to stick relay 52 so that front contact 55 for energizing relay 56 is maintained for a sufficient to provide full actuation of four-way valve 14. This tank circuit includes capacitor 61 and resistor 62. Capacitor 61 is initially charged by a voltage determined by the parameters of the system and specifically in proportion to the voltage of battery E. Capacitor 61 maintains relay 52 through front contact 54, diode 63 and through relay 52 winding back to the common terminal 53. The charging circuit for capacitor 61 includes battery E, wires 57 and 64, resistor 62 and capacitor 61 to common 53 and similarly when the machine is in the normal position N, capacitor 61 is receiving a charge from battery B through wires 57, 64', resistor 62 and capacitor 61' to common 53. When the machine is actuated to the reverse by a positive input on terminal 50', a charge built up on capacitor 61 performs the same function as previously described for capacitor 61. Capacitors 61 and 61 are charged respectively through resistors 62-62' each time the relays 52 and 52' drop out. These capacitors are normally charged respectively through resistors 62-62 each time the relays 52 and 52 drop out. These capacitors are normally charged for providing pickup energy for their respective relays.

Another set of operative components includes capacitors 61-61 65-65, resistors 66-66 and diodes 67-67. These are used in the power trailing operation of this device. As shown the device is in the normal position with magnet 28 adjacent to switch 27 drawing same to the extreme left or to its normally open contact. Battery 51 charges the capacitor 65' through resister 66'. The switch 27 remains at its normally closed position, the extreme left, when magnet 28 is adjacent to switch 27'. When the machine is trailed from the normal to the reverse, the actuator bar 14 exerts a force on alignment plate 22 to the lefi pulling on guide members 21-21 and subsequently yoke 20 for moving the collar 20 to the left. Magnet 28 ridding on collar 20 is thus pulled to the left. Contact 27' is thereby released from the influence of the magnet 28 and flips over to its normally closed extreme right position. Capacitor 65 having been charged by battery 51, discharges now through diode 67', relay 52 same for picking up contacts 54' and 55. The conditions as previously described for relay 52 similarly apply for energizing relay 52'. Actuation of relay 52 provides energy to rough contact 55' to relay 56', which operates fluid control valve 14. The energy stored in capacitor 65' proves sufficient to pick up relay 52'. When valve 14 is activated by relay 56' to the reverse mode, air is exhausted from the air bag 18 directed into the air bag 18 which forces the mechanism to shift from the normal to the reverse position. When the switch reaches the extreme left (reverse) position, contact 27 is pulled from its normally closed extreme left position to the extreme right, closing the circuit from the battery E through resistor 66 and capacitor 65 to common terminal 53, thus charging capacitor 65. If now the switch is again trailed, this time to the normal, the collar 20 is forced to the right and when the magnet is pulled, a short distance away from switch contact 27, it flips over to the left, normally closed contact, energizing relay 52 through diode 67. Again the solenoid 56 is energized through front contact 55 and four-way valve reverses the airflow causing air bag 18' to be emptied and 18 to be filled for throwing the switch points 12 to the right. Diodes 65 and 65 across relays 56 56 respectively provide for current suppression upon collapse of the associated field when either of said relays is deenergized. Diodes 68-68 prevent input current from tenninals 50 and 51' from interfering with the charging and discharging of capacitors 65 and 65' when either of said terminals 50 or 50 have a positive polarity imposed thereon and also provide for a path for an adequate ground or common connection from common terminal 53, when either of the input terminals 50-50' are negatively polarized.

The advantages of this type of system arise from the relatively small power needed for its operation, and the compact design of the system itself. The components were chosen to require a minimum amount of space in a circuit housing 30 mounted on top of the machine over 31 shown in FIG. 2. The preferred embodiment utilizes printed circuits and low power consuming solid state diodes for further minimizing the total space requirements of this system and substantially reducing the initial cost and overall maintenance expense. The invention therefore provides for a relatively small and inexpensive switch machine for use primarily in industrial yards where the cost of installation and maintenance must be kept to a strict minimum. There has also been provided a machine which is power trailing and virtually jam proof because even in the event of a failure for the machine to power trail over from one position to the other, the air bags 18 and 18' provide sufficient resilience to be able to withstand a forced trailing without destruction of machine or the switch points. Thus minimizing any repair costs in the event of an electrical circuit or fluid control valve failure. There has also been provided a machine utilizing a minimum number of mechanical components for performing a function which has heretofore required complex apparatus and linkages.

While there has been described what is considered to be the preferred embodiment of the present invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the scope of the invention.

I claim:

1. A trailable switch machine wherein a switch machine mechanism disposed therein actuates a set of railroad switch rails reciprocally to normal and reverse positions, said switch mechanism responsive to a control means for selectively actuating the mechanism to the desired position in accordance with an input signal, said control means comprising:

means magnetically responsive to the position of the switch rails including:

means magnet laterally disposed relative to the normal and reverse positions of the switch rails;

a switch means laterally disposed so as to cooperate with the proximity of the magnet, said switch means selectively actuating the control means for changing the position of the switch rails to the opposite position when the relative positions of the switch means and the magnet is altered by trailing of the switch points; and

energy storage means for maintaining said input signal for a period relative to a minimum actuation time of said control apparatus.

2. The trailable switch machine of claim 11, including: two compressible fluid containing bodies for driving said switch machine mechanism to the forward and reverse positions when one or the other of said bodies is filled with said fluid.

3. The trailable switch machine of claim 2, wherein the control apparatus includes: fluid control means momentarily actuated for selectively filling and emptying one or the other of said bodies in accordance with the desired position; and the energy storage means maintaining said momentary actuation regardless of the duration of the input signal.

4. The railroad switch machine of claim 3, wherein said fluid control means is an electrically actuated four-way valve and said energy storage means is an electrical tank circuit.

5. The railroad switch machine of claim 2, connected to the switch points by an actuator bar including:

a housing having a laterally disposed guide way therein,

an operating mechanism disposed on the housing adapted to provide the reciprocation of the switch points in alignment with the guide way; and

a yoke reciprocally slidably mounted in said guide way attached to opposite ends of the compressible fluid bodies, said bodies fixed at the other ends to the housing for sliding the yoke reciprocally when one or the other of said bodies is filled with fluid.

6. The trailable switch machine of claim 5, wherein said yoke comprises;

a collar mounted to the compressible body;

a guide member slidably mounted in the guide way and fixed at one end to the collar and at the other end to the actuator bar for reciprocal movement in said guide way.

7. The trailable switch machine of claim 6, wherein the guide member includes: two pins fixed at one end perpendicular to the collar and at the other joined to the actuator bar; and the guide way includes a member having two holes therein for sliding the pins therethrough, with the direction of movement of the switch points. 

1. A trailable switch machine wherein a switch machine mechanism disposed therein actuates a set of railroad switch rails reciprocally to normal and reverse positions, said switch mechanism responsive to a control means for selectively actuating the mechanism to the desired position in accordance with an input signal, said control means comprising: means magnetically responsive to the position of the switch rails including: means magnet laterally disposed relative to the normal and reverse positions of the switch rails; a switch means laterally disposed so as to cooperate with the proximity of the magnet, said switch means selectively actuating the control means for changing the position of the switch rails to the opposite position when the relative positions of the switch means and the magnet is altered by trailing of the switch points; and energy storage means for maintaining said input signal for a period relative to a minimum actuation time of said control apparatus.
 2. The trailable switch machine of claim 1, including: two compressible fluid containing bodies for driving said switch machine mechanism to the forward and reverse positions when one or the other of said bodies is filled with said fluid.
 3. The trailable switch machine of claim 2, wherein the control apparatus includes: fluid control means momentarily actuated for selectively filling and emptying one or the other of said bodies in accordance with the desired position; and the energy storage means maintaining said momentary actuation regardless of the duration of the input signal.
 4. The railroad switch machine of claim 3, wherein said fluid control means is an electrically actuated four-way valve and said energy storage means is an electrical tank circuit.
 5. The railroad switch machine of claim 2, connected to the switch points by an actuator bar including: a housing having a laterally disposed guide way therein, an operating mechanism disposed on the housing adapted to provide the reciprocation of the switch points in alignment with the guide way; and a yoke reciprocally slidably mounted in said guide way attached to opposite ends of the compressible fluid bodies, said bodies fixed at the other ends to the housing for sliding the yoke reciprocally when one or the other of said bodies is filled with fluid.
 6. The trailable switch machine of claim 5, wherein said yoke comprises; a collar mounted to the compressible body; a guide member slidably mounted in the guide way anD fixed at one end to the collar and at the other end to the actuator bar for reciprocal movement in said guide way.
 7. The trailable switch machine of claim 6, wherein the guide member includes: two pins fixed at one end perpendicular to the collar and at the other joined to the actuator bar; and the guide way includes a member having two holes therein for sliding the pins therethrough, with the direction of movement of the switch points. 